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Clinical aspects of nerve damage in leprosy

Theuvenet, W.J.

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Citation for published version (APA):Theuvenet, W. J. (2002). Clinical aspects of nerve damage in leprosy.

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Download date: 30 Mar 2020

Chapterr 6

Thee Paper Grip Test for Screening on Intrinsicc Muscle Paralysis in the Foot

off Leprosy Patients From:: The Paper Grip Test for Screening on Intrinsic Muscle Paralysis

inn the Foot of Leprosy Patients Maartjee MX. de Win, Wim J. Theuvenet, Paul W. Roche, Rob A. de Bie

andd Henk van Mameren Intt J Lepr, 2002; 70(1) : 16-24.

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INTRODUCTION N

Foott problems are one of the most common causes of 'dehabilitation' and morbidity in lep-rosy.. Mostly, there is a combination of sensory, motor and autonomic nerve affection result-ingg in progressive loss of protective sensation, weakness and muscle atrophy.12 Approxi-matelyy 10% to 15% of leprosy patients have impairments and disabilities involving their feet,, especially plantar ulceration, drop-feet, claw feet and tarsal disorganisation.23

Recurrentt ulceration in spite of protective footwear is the most frequent indication for admissionn in leprosy hospitals.

Althoughh a lot of attention is paid to anaesthesia of the foot sole as a cause of foot problems inn leprosy and other neuropathies of the foot, less attention is paid to paralysis of the intrin-sicc muscles. However, it is thought that anaesthetic feet without intrinsic muscle paralysis aree not prone to ulceration.24 As paralysis of the intrinsic muscles of the hand leads to claw hands,, paralysis of the plantar intrinsic musculature of the foot leads to claw toes.12 Intrinsic muscless contribute to the architecture of the longitudinal and transverse arches of the foot, whichh aid in the distribution of mechanical stresses especially during walking.3'19,20

Paralysiss wil l lead to abnormal foot structure and increased peak-loads. Clawing of the toes duee to intrinsic muscle paralysis also causes a shift in distal direction of the plantar fat pad beloww the metatarsophalangeal (MTP) joint, exposing the thinner part of the skin to pres-sure.77 Therefore, additional intrinsic muscle paralysis increases the risk of ulceration in anaestheticc feet by a factor of 10 to 12.23 The combination of anaesthesia and paralysis is foundd in 85% of all ulcers; the majority is located in the forefoot, especially in the MTP jointt region.8-23 Infectious conditions, like osteomyelitis, septic arthritis and septic ten-dosynovitiss are most common complicating factors causing further deformation.14

Inn the early stage of intrinsic muscle paralysis, education, self-care and special footwear can helpp prevent further deformities.4'15,21'22 Moreover, claw toe deformity and its consequences mayy be prevented and corrected by tendon transfer surgery, employing the long flexor of eachh digit. This procedure is only possible in flexible claw toe deformities and is preferable too procedures used for fixed claw toe deformities (arthrodesis with or without shortening of thee toe) because it provides a partial restoration of function.13 Thus, just as with the early detectionn of sensibility loss, die early detection of intrinsic muscle paralysis has important implicationss for the prevention of impairment and deformity. In spite of this, there is no reliablee manual test that can be used as a screening test for intrinsic muscle strength in lep-rosyy patients, unlike the routine tests that are done for the examination of the extrinsic mus-cless or the sensibility of the foot.

Thee lack of a reliable screening test gave rise to the development of the Paper Grip Test (PGT)) by W. J. Theuvenet and P.W. Roche, from The Anandaban Leprosy Hospital, The Leprosyy Mission, Nepal in 1990. This PGT can be used as a screening test for plantar intrin-sicc foot muscle paralysis. The PGT resembles the Froment test for detection of intrinsic

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CHAPTERR 6

handd muscle paralysis, where the patient has to hold a piece of paper between the pulp of thee thumb and that of the index finger while the examiner tries to pull it away.25 This test becomess positive when the adductor pollicis, the first dorsal and the second palmar interos-seii muscles are paralysed, because the patient in an effort to hold on to the sheet, wil l flex thee distal phalanx of the thumb before losing grip of the paper. In the PGT for the hallux, thee patient wil l try to hold a piece of paper pressed between the pulp of the big toe and the floor,floor, while the examiner tries to pull it away. If the flexor hallucis brevis is paralysed, the patientt wil l flex the distal phalanx of the hallux before losing grip of the paper.

Thee purpose of this study was to investigate the reliability of the PGT as a screening test for intrinsicc muscles weakness of the foot. We investigated the outcome of the PGT in leprosy patientss compared to non-leprosy controls. Also, the correlations between the outcome of thee PGT's and different factors such as foot sole sensibility, gender, age and type of leprosy weree objectives of this study.

MATERIAL SS AND METHODS

Thee Paper Grip Test Twoo variants of the PGT were conducted, PGT1 to detect intrinsic muscle weakness of the greatt toe and PGT2 to detect weakness of the combined intrinsic muscles of the lesser toes (second,, third, fourth and fifth toe).

Thee Paper Grip Test of the great toe (PGT1). A paperr slip is put under the great toe just distal to thee MTP joint. While the examiner tries to pull thee paper away, the patient offers maximal resist-ance.. The hand of the examiner rests on the patient'ss knee assuring the heel is kept on the floor.

Duringg the test the person (footwear and socks removed)) sits up straight with hips, knees and ankless in 90° of flexion. The examiner supervises thatt patients stay in the same position and keep theirr heels on the floor during the test. Patients havee to look at their feet, because leprosy patients withh anaesthetic feet will not feel the paper, caus-ingg difficulty in holding the paper. Thee examiner puts a slip of strong rough paper underr the phalanges of respectively the great toe (forr the PGT1) or the four lesser toes (for the PGT2),, just distal to the MTP joints (see photo-

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graph).. The examiner tries to pull the paper away with gradually increasing power in a hori-zontall direction, while the person offers resistance. Solid rough paper (2x10 cm, 100g/m2

type)) that did not easily tear, and a smooth underground of concrete was used in all exam-inations. .

Thee PGT was carried out up to three times when the patient was not able to grip the paper. Thee PGT was considered positive (abnormal), when it was possible to pull die strip away easilyy all three times. The test was considered negative (normal) when the patient was able too grip the paper at least one out of three times testing.

Patientss and controls Inn 1998, during a period of four months, leprosy patients (new patients and patients who camee for follow-up) and non-leprosy subjects from the Purulia Leprosy Home and Hospital (Thee Leprosy Mission, Purulia, West Bengal, India) were examined for their intrinsic mus-clee function. Patients with paralysis of the long flexors and extensors of the toes, infective ulceration,, rigid claw toes or other gross deformities were excluded. Patients widi small non-infectivee ulcerations were not excluded. The non-leprosy subjects were volunteers without foott deformities, selected from the same background (family members of the patients and personss matched for social standing) in order to prevent bias due to different types of feet andd footwear.

5177 leprosy patients and 170 non-leprosy controls met the inclusion criteria. Information aboutt age (<20, 20-39, 40-59 and >59) and type of leprosy (TT= tuberculoid leprosy, BT= borderlinee tuberculoid leprosy, BB= borderline leprosy, BL= borderline lepromatous leprosy, LL=lepromatouss leprosy, PN= pure neuropathic leprosy) was obtained of each person. The proportionn of males was 67.4% in the leprosy group and 66.5% in the control group. A majorityy of males corresponds with the general gender-distribution of leprosy.11 The mean agee was 30.3 years in a range from 4 up to 81 years old. Of those 517 leprosy patients, 496 mett the criteria for both feet and 21 patients for only one foot, so a total amount of 1013 leprosyy feet were included in die study. The results of these 21 patients were only regarded inn the analysis of the relation between outcome of the PGT and foot sole sensibility. The otherr analysis required both feet to be included (n=496).

Extrinsicc muscle testing Functionn of the tibialis anterior, the extensor digitorum longus, the extensor hallucis longus, thee flexor digitorum longus, and die flexor hallucis longus were tested by means of isomet-ricc contraction against resistance in unloaded feet.6 For testing of the tibialis anterior, exten-sorr digitorum longus and the extensor hallucis longus, the patient had to move feet and toes dorsally,, while the examiner offered resistance to extension of the toe and fixed die ankle in 90°° of flexion. For testing the flexor digitorum longus and flexor hallucis longus the patient movedd his toes plantarwards, while the examiner offered resistance to the distal phalanges andd fixed the proximal phalanges in a flexed position to relax the intrinsic muscles.

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Sensibilityy testing Sensibilityy of the foot sole was tested by means of a 10 gram Semmes-Weinstein monofila-ment.55 This has been described to be a reproducible method for detecting loss of protective sensationn of the sole of the foot.17 After adequate explanation and demonstration, sensibil-ityy was tested at three regions: the first metatarsal head (medial plantar nerve), the fifth metatarsall head (lateral plantar nerve), and the heel pad (tibial nerve). The examiner gave a stimuluss up to three times at each region. Sensibility was regarded normal when a patient waswas able to indicate all three regions of pressure stimulus with closed eyes at least one out of threee times tested. A foot was regarded partially anaesthetic when the patient was able at leastt once to indicate the pressure stimulus at either one or two regions, and as totally anaes-theticc when the patient was not able to indicate the pressure at any of the three regions.

Examiners s Too diminish information bias, two examiners performed examination. The first examiner determinedd whether patients and controls met the inclusion criteria. This examiner also determinedd the function of the plantar intrinsic muscles of the foot by means of the PGT1 andd 2. The second examiner, a physiotechnician of the hospital staff, performed sensibility testingg of the sole of the foot as part of a three monthly routine check up for leprosy patients. AA third examiner was involved to measure the inter-observer variability of the PGT.

Validityy and reliability of the Paper Grip Test Inn seven leprosy patients with loss of protective sensation of the forefoot but normal PGT 1 andd seven non-leprosy subjects with normal PGT 1 an experiment was done to test the valid-ityy of the PGT in determining plantar intrinsic muscle paralysis of the foot. In all 14 persons thee tibial nerve of one foot was artificially blocked by injecting 5cc bupivacaine 1% inside thee tarsal tunnel. After that the PGTl testing was repeated.

Inn three healthy persons we tested the activation of the plantar intrinsic muscles and long muscless of foot and toes, while performing the PGTl by means of surface electromyogra-phy. .

Inter-- and intra-observer reliability was determined on the basis of the results of the exami-nationss of 20 leprosy patients (n=40 feet) independently by the first and third examiner, alternatelyy just after each other. Intra-observer variability was determined by examining 43 leprosyy patients (n=86 feet) twice by the same examiner on two separate occasions with an intervall of about three months.

Dataa analysis Thee bivariate Pearson correlation-analysis was used to detect linear relations between out-

comess of the PGT's and leprosy, foot sole sensibility, gender, age and type of leprosy.

Throughh this analysis it is possible to present the relation between two variables, correcting

itt for other variables by means of the partial correlation coefficient (pec). A p-value <0.05

waswas regarded as significant.'

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Agreementt in inter- and intra-observer examinations was analysed separately for PGT1 and 22 through the non-weighted Cohen's kappa coefficient (/-value) for two categories (PGT positivee either negative).2

RESULTS S

PGTT in leprosy patients and controls, specificity of the PGT

% % 100--

9 0 --

80 0

7 0 --

6 0 --

80 --

4 0 --

3 0 --

2 0 --

10--

0 ^ ^

318 8

H H bprns yy non-fepros y lepros y non-lepros y

PGT11 PQT2

BB both feel abnorma l I one toot abnorma l D both feet norma l

Fig.. 1. positive PGT1 of the great toes and PGT2 of the lesser toes in leprosy patients and non-leprosyy controls. Numbers in the columns present absolute amounts of persons.

Figuree 1 shows that 35.9% of the leprosy patients (n=496) had a positive PGT1 and 49.6% aa positive PGT2 of one or both great toes. In comparison, in the control group (n=170), 7.1%% had a positive PGT1 and 17.6% a positive PGT2 of one or both great toes. Corrected forr gender and age, significantly more leprosy patients than non-leprosy controls had a pos-itivee test (pcc=0.29 and p<0.01 for both PGT1 and PGT2). Positive tests in the control groupp can be regarded as false positive tests, so from these results specificity can be calcu-lated.. Sixteen (2x4 + 8) false positive results in 340 tested feet give a specificity of 95.3% for PGT1,, and 47 (2x17 +13) false positive results in 340 tested feet give a specificity of 86.2% forr PGT2.

Influencee of sensory loss, gender, age and leprosy type on the outcome of the PGT Too examine the relation between a positive PGT and loss of foot sole sensibility all feet of leprosy-affectedd people were regarded separately. These were divided into three groups accordingg to the degree of sensibility loss of the foot sole.

1M M

H H

280 0

140 0

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CHAPTERR 6

100--

90 90

80 0

70" "

6 0 --

50 --

4 0 --

30 0

20--

10--

456 6

j j

7 7

1 1 norma ll partia l

sensibilit yy anaesthesi a

PGT

PGT

D P G T T

lan dd F

lorP G G

land P P

QT22 abnorrrB t

722 abnorma l

GT22 norma l

30 0

„ „

1 1 H H I I 1 1 total total

anaesthQs e e

Fig.. 2. positive PGT1 of the great toes and PGT2 of the lesser toes in the feet (n=1013) of leprosyy patients with different levels of foot sole anaesthesia; normal sensibility (n=606),, partial anaesthesia (n=211), total anaesthesia (n=196). Numbers in the columnss present absolute amounts of feet

Figuree 2 shows that 71.3% of the total anaesthetic feet had a positive PGT of both great and lesserr toes (positive PGT1 and PGT2). In the group of partial anaesthetic feet 33.2% had a positivee PGT1 and PGT2, while 25.6% showed either PGT1 or PGT2 positive. Leprosy feett with a normal sensibility showed a positive PGT1 and/or PGT2 in 24.8%. The relation betweenn degree of sensibility loss and a positive PGT proves to be significantly correlated afterr correction for gender, age and type of leprosy (pcc= 0.49, p<0.01).

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100 0

90 0

80 0

7 0 --

60 0

50 0

40 0

30 0

20 0

1 0 --

0 --mate e female female male e temate temate

nan-teproe y y

PGT1 of one or both great toes abnormal

OO PGT1 of both greal toes normal

Fig.. 3. intrinsic muscle weakness of the great toes in males and females in both leprosy patientss (N=496) and non-leprosy controls (N=170). Numbers in the columns pres-entt absolute amount of persons.

Thee presentation of a positive PGT test among males and females in both leprosy and non-leprosyy groups is shown in figure 3. Female leprosy patients turned out to have a higher prevalencee of a positive PGT of one or both great toes (46.0%) than male leprosy patients (31.0%).. After correction for age and type of leprosy this relation proved to be significant (pcc== 0.21, p<0.01). In the non-leprosy group these values were 14.0% for females and 3.5%% for males (pcc= 0.24, p<0.01).

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< 2 00 20-39 40-S8 >59

tep-osy tep-osy

II one or both gnat lose abnormal

< 2 00 20-39 40S9 !

ncn- leprosy y

DD both graal toee normal

Fig.. 4. positive PGT1 of the great toes in different age groups in leprosy patients and non-leprosyy controls. Numbers in the columns present absolute amounts of persons.

Figuree 4 shows that the prevalence of a positive PGT increases with older age. PGT1 was positivee in 49.5% of leprosy patients in the age group 40 - 59, against 21.0% positive tests inn the age group up to 19. After correction for gender and type of leprosy the relation betweenn a positive PGT1 and age proves to be significant for both leprosy group (pcc= 0.22, p<0.01)) and control group (pcc=0.19, p=0.01).

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BTT BB BL LL PN differen tt type s of tnpw y

II on e or bert h grea t b e e abnorma l O boihgree i toe e norma l

Fig.. 5. positive PGT1 of the great toes in different types of leprosy. Numbers in the columnss present absolute amounts of persons.

Thee distribution of a positive PGT among different types of leprosy is shown in figure 5. Thee percentages of patients with positive PGT1 of one or both feet varies significantly per typee of leprosy after correction for gender and age (pcc=0.l6, p<0.01). The highest per-centagess of a positive PGT were found among patients with PN, BB and LL type of leprosy. AA positive PGT1 in TT type of leprosy (14.3%) is two times higher than in non-leprosy patientss (7.1%, fig-1)-

Validityy and reliability of the Paper Grip Test Inn both leprosy patients and non-leprosy subjects the PGT1 changed from negative (nor-mal)) to positive (abnormal) in all 14 feet tested, after blocking the tibial nerve inside the tarsall tunnel with 5cc bupivacai'ne 1%. The long flexors of the foot and toes remained unaf-fected. .

Electromyographyy in three healthy persons confirmed that the plantar intrinsic muscles weree used in testing with the PGT. However, also long flexors of foot and toes showed elec-tromyographicc activity. Thee <?-value for the inter-observer reliability (non-weighted, 2 categories, n= 40 feet) is cal-culatedd at 0.87 [95% CI: 0.69-1.04] for PGT1 and 0.61 [95% CI: 0.34-0.87] for PGT2. Thee f-value for the intra-observer reliability (non-weighted, 2 categories, n= 86 feet) is cal-culatedd at 0.56 [95% CI: 0.36-0.76] for both PGT1 and 0.56 [95% CI: 0.39-0.74] for PGT2. .

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CHAPTERR 6

DISCUSSION N

Validity,, specificity and reliability of the PGT Thee results of the experiment, before and after the block of the tibial nerve at the level of thee tarsal tunnel (unaffecting the long flexors and extensors of foot and toes), show that the PGTll is capable to selectively demonstrate intrinsic foot muscle weakness. The EMG exper-imentt shows that also extrinsic muscles were activated during the PGT but by assuring nor-mall strength of the long flexors in all our subjects there was no difference between our sub-jectss regarding extrinsic muscle function.

Thee specificity of 95.3% for PGTl found in this study can be considered as high compared too that of other manual muscle strength tests.16 There is a lower specificity of PGT2 (86.2%)) than PGTl. To prevent many false positive results the PGTl is probably a better screeningg method to detect intrinsic muscle weakness than the PGT2. However, the two testss do not provide identical information, so another possibility, explaining the higher per-centagess of positive PGT2 than PGTl in the leprosy group, is that the lateral plantar nerve iss more often affected by leprosy than the medial plantar nerve.

Thee inter-observer agreement can be regarded as good for PGTl and moderate/good for the PGT2.. This is comparable to the intertester reliability of otherr manual muscle strength test-ingg used in leprosy9, but the number of patients was small. The intra-observer reliability is moderatee for both PGTl and PGT2.2 When the moderate K value really reflects the intra-reliabilityy of the PGT, this is a relative weakness of the PGT. However, the moderate repro-ducibilityy may also be caused by actual changes in muscle function during the long interval betweenn the first and second measurement (about three months). Especially in the begin-ningg phase of multidrug therapy nerve reactions that cause changes in muscle function may occur. .

Thee correlation that we found between both age and type of leprosy and positive PGT's is similarr to the correlation between several disabilities, based on peripheral nerves affection, andd age and type of leprosy described in other studies.10-18

Thee use of the PGT as a screening test for intrinsic muscle paralysis of the foot Thee PGT can be a valuable addition to the physical examination of leprosy outpatients. It

iss a simple, cheap and non-invasive test that does not require additional equipment. These

propertiess make the test especially suitable for screening on the function of plantar intrinsic

foott muscles in leprosy patients in hospitals and during fieldwork in developing countries.

Fromm our results we conclude that screening of leprosy patients with PGT's additional to

sensibilityy testing is very important. Firstly, because we found that the intrinsic muscles of

thee great toe are affected in more than one-third of the leprosy patients without gross defor-

mities.. Secondly, because many partially anaesthetic feet appeared to have intrinsic muscle

weakness.. Thirdly, in this study intrinsic muscle weakness of both great and lesser toes is

foundd in more than 70% of the total anaesthetic feet, making them especially vulnerable to

ulceration.. On the other hand, 15% of the patients with total anaesthetic feet has strong

intrinsicc muscles making them less vulnerable to ulceration.24 The care of these patients in

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thee long-term could be limited to regular control of the skin of the foot and the use of pro-tectivee footwear. Late development of plantar paralysis long after cure of the disease is quite rare.. Fourthly, because the PGT may give early warning of nerve function impairment in patientss with intact foot sole sensibility measured by a 10 grams monofilament method.

Clinicall consequences of a positive PGT- prevention of foot deformity Whenn impaired intrinsic muscle function of the foot is detected by means of the PGT screeningg method, this has important clinical consequences. An early sign of loss of intrin-sicc muscle function deserves the same treatment as for instance signs of ulnar nerve neuri-tis.. Apart from the attempt to treat the neuritis e.g. with corticosteroids, other measures to preventt deformity of the foot are necessary. When a patient has a positive PGT, a Harris mat printt can be used, if available, to detect changes in the weight bearing areas8 as an indica-tionn to adapt the footwear. Special protection of especially the metatarsal area can be created byy e.g. the provision of a rigid sole, which will prevent stress to the metatarsal pads during thee push-off phase of walking. In a flat terrain also a rocker mechanism can be considered. Thee insole should provide support to the longitudinal arch by an arch-support, to the trans-versee arch and the metatarsal heads by a metatarsal button, and add stability to the heel by aa heel cup. Signs of collapse of the longitudinal arch can be detected by measuring a decreas-ingg projection height of the medial malleolus of the weight bearing foot. In an early stage of claww toes, when the toes are still mobile, a tendon transfer is possible to prevent further claw-ingg of the toes.13

Limitationss of the PGT and recommendations for improvement Thee lack of another reliable, non-invasive clinical test that measures intrinsic muscle strengthh with which the PGT could be compared, is a limitation of this research. Because wee could not compare the PGT to another test, it was not possible to assess the sensitivity off the PGT. The only reliable gold standard would be needle electromyography, which we didd not use in this study. Surface electromyography showed not only electromyographic activityy in the intrinsic muscles but also in the long muscles of the toes. But, by assuring normall strength of the long flexors in all our subjects, a positive PGT caused by weak extrin-sicc muscles is excluded. Thee first examiner performed the inclusion of patients and PGTs so the outcome of the PGTss was potentially vulnerable to information bias due to knowledge of variables as lep-rosy/non-leprosyy and type of leprosy. During examination of the foot this examiner also becamee aware of ulcerations of the foot. This bias was limited by emphasising to all subjects too give as much pressure to the paper slice as they could. Falsee positive PGT s may be caused by generally small muscle power and/or persons' mis-understandingg of the test procedure. This may also explain the higher percentages of posi-tivee PGT's in older people and females in both leprosy and control groups. Moreover, femaless were less inclined to give firm resistance with their feet in reaction to the pulling of thee paper.

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AA relatively high proportion of feet of leprosy-affected persons with no loss of plantar sensi-bilit yy was found to have positive PGTs (PGTl 10.7%, PGT2 23.1%). Partially this could bee explained by false positive results of the PGTs, but in the control group the proportions off positive PGTs are significantly lower. This could probably be explained by the relatively loww sensitivity of the 10 grams monofilament sensibility test for mild sensibility loss of the footsole.. More sensitive sensibility testing, with a 2 grams monofilament for example, shouldd be performed in these patients. Also, sensibility was regarded as normal when a patientt was able to indicate all three regions of pressure stimulus with closed eyes at least one outt of three times. This wil l not eliminate some errors due to guessing so this could have leadd to underestimation of sensibility loss in the leprosy group.

Thee exclusion of patients with foot deformities gives an underestimation of the percentage off leprosy patients with intrinsic muscle weakness. It is likely that the majority of them has paralysisparalysis of intrinsic foot muscles.

Thee influence of the use of different types of paper slips and different types of underground iss not investigated in our study. When the paper slip used is too thin, the tearing point of thee paper wil l become critical to identifying the threshold for a negative test. Therefore we recommendd standardisation of the paper quality and paper size. We would advise the size andd type that is used for business cards ( at least 100 g/m2), as this paper wil l not easily tear andd is widely available. Also the direction and rate of force, the area the force is applied to thee paper and testing surface could probably influence the outcome of the PGT We rec-ommendd standardisation of these as a further objective of study.

Itt would also be interesting to correlate the PGT results with additional variables such as presencee of ulcer/scar at certain sites and site of anaesthesia to increase the validity of the PGT. .

SUMMARY Y

Plantarr intrinsic foot muscles provide structure to the foot during walking and thus regulate mechanicall foot sole stresses. When paralysed, for instance in leprosy patients with neu-ropathyy of the distal part of the tibial nerve, there is a high prevalence of plantar ulceration andd deformities, especially when muscle weakness goes together with loss of foot sole sensi-bility .. These patients should get immediate care involving education, special footwear and reconstructivee surgery before further foot impairment and deformity become manifest. Thus far,, in leprosy patients littl e attention is paid to screening of plantar intrinsic muscles activ-ity.. This can be done with a new simple and non-invasive method, the Paper Grip Test

(PGT).(PGT). There are two variants for detecting intrinsic muscle weakness of the foot, PGTl for thee great toe and PGT2 for the combined lesser toes.

Inn this study, 517 leprosy patients and 170 healthy volunteers were investigated with the PGT.. Sensibility of the foot sole was tested by means of a 10 grams monofilament. Specificityy of the PGTl is found to be about 95.3%, which is good for physical diagnostic tests.. PGT2 is less specific than PGTl. Individual muscle power and understanding of the

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patientt seems to influence the outcome of the test to a certain extent. Sensitivity can only bee calculated when the diagnosis is confirmed by electromyography. Especiallyy patients with anaesthetic feet, females, older patients and patients with PN, BB orr LL types of leprosy appeared to have a higher prevalence of intrinsic foot muscle weak-ness.. All results were analysed by means of the bivariate Pearson correlation-analysis and provedd to be statistically significant (p<0.05). It is concluded that the PGTl, more than the PGT2,, is a useful screening test on the function of plantar intrinsic foot muscles in leprosy patientss in hospitals and during fieldwork in developing countries.

ACKNOWLEDGEMENTS S

Thee authors want to thank The Leprosy Mission International and The Leprosy Mission Purulia.. Especially Dr. Kiran Sarkar, reconstructive surgeon, for supervision during the project,, and the physio-technicians of the Purulia hospital staff for their help in sensibility testingg and translation. We also want to thank Prof. Dr. F.G.I. Jennekens for his valuable remarkss on the manuscript.

Fundingg for this project has been provided by Universiteitsfonds Limburg / SWOL and the medicall faculty of Maastricht University.

References: : 1.. Altman DG.

Correlation. .

In:: Practical Statistics for Medical Research.

London:: Chapman and Hall; 1991. p. 278-291.

2.. Altman DG.

Inter-raterr agreement.

In:: Practical Statistics for Medical Research.

London:: Chapman and Hall; 1991.p. 403-409.

3.. Basmajian JV and Stecko G.

Thee role of muscles in arch support of the foot: An electromyographic study.

JJ Bone Joint Surg 1963;45(A):1184-1190.

4.. Bauman JH, Girling JP and Brand PW.

Plantarr pressures and trophic ulceration.

JJ Bone Joint Surg 1963;45(B):652-658.

5.. Birke JA and Sims DS.

Plantarr sensory threshold in the Hansen's disease ulcerative foot.

Readd at the Proceedings of the International Conference on Biomechanics and Clinical Kinesiology of Hand

andd Foot; Madras, India; 1985.

6.. Boumans MTA and van Ooy A.

Hett onderzoek van de voet.

In:: Lege artis: het onderzoek van de onderste extremiteiten.

Utrecht:: Wetenschappelijke uitgeverij Bunge; 1995. p. 47-68.

7.. Brand PW.

Thee insensitive foot (including leprosy).

In:: Jahss MH , Disorders of the Foot.

Philadelphia:: W.B. Saunders Company; 1982. p. 1266-1286.

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8.. Brand PW.

Insensitivee feet; a practical handbook in leprosy.

London:: The Leprosy Mission; 1989.

9.. Brandsma JW, van Brakel WH., Anderson AM , Kortendijk AJ, Gurung KS, and Sunwar SK.

Intertesterr reliability of maual muscle strength testing in leprosy patients.

Leprr Rev 1998;69:257-66.

10.. Browne SG.

Somee less common neurological findings in leprosy.

Intt J Lepr 1965;33 :267-272.

11.. de Vries JL and Perry BH.

Leprosyy case detection rates by age, sex and polar type under leprosy control conditions.

Amm J Epidemiol 1985;121:403-413.

12.. Enna CD.

Peripherall Denervation of the Foot.

Neww York: Allan R. Liss; 1988.

13.. Fritschi EP.

Surgicall Reconstruction and Rehabilitation in Leprosy.

Neww Delhi: The Leprosy Mission; 1984.

144 Harris JR and Brand PW.

Patternss of disintegration of tarsus in the anaesthetic foot.

JJ Bone Joint Surg 1966 ;48 (B) :4-16.

15.. Harris JR and Browne SG.

Thee management of dry skin in leprosy patients.

Lancett 1966;1:1011-1013.

16.. K i m S H . H a K I, Han, KY.

Bicepss load test: a clinical test for superior labrum anterior and posterior lesions in shoulders with recurrent

anteriorr dislocations.

Amm J Sports Med 1999;27:300-3.

177 Kumar S, Fernando DJS, Veves A, et al.

Semmes-Weinsteinn monofilaments: a simple, effective and inexpensive screening device for identifying

diabeticc patients at risk of foot ulceration.

Diabetess Research and Clinical Practice 1991;13:63-68.

188 Kuswah SS, Govila AK, and Kuswah J.

Ann epidemiological study of disabilities among leprosy patients attending leprosy clinic in Gwalior.

Leprr India 1981;53:240-247.

199 Mann RA.

Biomechanicss of the foot.

In:: Jahss, Disorders of the Foot.

Philadelphia:: W.B. Saunders Company; 1982. p. 37-67.

20.. Mann R and Inman VT.

Phasicc activity of intrinsic muscles of the foot.

JJ Bone Joint Surg 1964;46(A):469-481.

211 Neville PJ.

AA guide to health education in leprosy.

Würzburg:: German Leprosy Relief Association; 1980.

22.. Neville P J.

AA foorwear manual for leprosy control programs, No I & II .

Würzburg:: German Leprosy Relief Association; 1980.

23.. Srinivasan H.

Disability,, deformity and rehabilitation.

In:: Hastings, Leprosy.

Edinburgh:: Churchill Livingstone; 1994. p. 411-447-

116 6

THEE PAPER GRIP TEST

244 Srinivasan H. Trophicc ulcers in leprosy II . Intrinsic muscles of the foot and trophic ulcers. Leprr India 1964;36:110-118.

25-- Tubiana R, Thomine JM, and Mackin E. In:: Examination of the hand and wrist. London:: Martin Dunitz Ltd; 1996. p. 326-327.

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CHAPTERR 6

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